The present invention relates generally to material handling equipment. More specifically the present invention relates to an arrangement for the raising and transporting of packing container blanks from a first to a second position by a movable carrier device.
Within the branch of the packaging industry which is concerned with the packing of certain types of liquid goods, e.g. milk, into consumer packages of the non-returnable type, packing machines are used which convert prefabricated packing container blanks into packing containers, which subsequently are filled directly with the desired contents and sealed. The packing container blanks are fed to the machine in the form of flattened tubular blanks which, prior to conversion to individual packing containers, have to be "raised", that is to say converted to four-sided tubes of substantially square cross-section. This conversion or raising usually takes place at the same time as the transfer of the blank from a magazine at the inlet end of the packing machine to a first processing station in the packing machine proper.
A known arrangement for the raising and transporting of a packing container blank at the inlet end of a packing machine is described in U.S. Pat. No. 3,785,113. The arrangement comprises a substantially vertical magazine for flattened packing container blanks and a conveyor situated in the vicinity of the lower end of the magazine for the transport of the raised packing container blanks one at a time to a mandrel wheel in the packing machine proper. At the lower end of the magazine there is a movable carrier device, provided with pneumatic suction heads, which is rotatable substantially 1/4 turn between a first position directly next to the lower end or outlet of the magazine and a second position close to the starting end of the conveyor. The arrangement also includes a support, situated outside the arc-shaped path of movement of the carrier device, intended to co-operate with and to raise a packing container blank which is transported by the carrier device from the outlet end of the magazine to the conveyor. Since the carrier device grips a flattened container blank situated in the magazine from underneath and during the raising and transport, so to speak, drags it along, the blank, after it has been placed in raised condition onto the conveyor, has to be carried off by the same before the carrier device can perform its return stroke. Otherwise, the raised blank situated on the conveyor would hinder the return stroke. This is a disadvantage which brings with it a reduction of the overall operating speed of the arrangement. The operating speed is also limited by the speed at which the raised packing container blank is transported by the conveyor.
A further known arrangement for the raising and transporting of packing container blanks on packaging machines is described in U.S. Pat. No. 3,937,131. This arrangement too is designed so that from a magazine with a number of flattened packing container blanks, one blank at a time is transferred, with simultaneous raising, to a feeding station in a packaging machine. In this construction it was attempted to overcome the abovementioned speed-reducing disadvantage by making the carrier device move, not in a reciprocating movement, but on a rotary path along which is arranged an external support in such a manner that it acts upon and raises the passing packing container blanks. By this the need for a return stroke is eliminated, and the arrangement, therefore, can operate at a relatively high speed. However, the arrangement becomes relatively complicated, since it has to include a number of different carrier and guide elements. The method allowing the carrier device to perform the work, that is to say, the transporting and raising of the packing container blank during the greater part of one whole rotation, also means that the arrangement will be extremely space-demanding and therefore unsuitable for use in modern, compact packaging machines.
It is a main object of the present invention to provide an arrangement for the raising and transporting of packing container blanks, which arrangement is not subject to the disadvantages of similar arrangements described above, but can operate at high speed without being hindered by raised packing container blanks fed previously.
It is a further object of the present invention to provide an arrangement of the abovementioned type, which is compact in its construction and operates within a limited range of movement.
It is a still further object of the present invention to provide an arrangement which is less complicated than similar arrangements known previously and therefore more reliable in operation and less expensive.
These and other objects have been achieved in accordance with the invention in that an arrangement for the raising and transporting of packing container blanks from a first to a second position by a movable carrier or transport device includes a support or unfolding structure adapted to co-operate with the passing packing container blanks. The unfolding structure is arranged within the range of movement of the carrier device.
A preferred embodiment of the arrangement in accordance with the invention, which is intended first and foremost for the raising and transporting of flattened tubular packing container blanks from a magazine to a conveyor by a carrier device, has been given the further characteristic that the carrier device includes a carrier plate which, while retaining its positional orientation, is adapted so as to be moved along a substantially arc-shaped path of movement between a first position at the outlet end of the magazine and a second position at the starting end of the conveyor. The support, which is adapted to co-operate with and to raise the passing packing container blanks, is situated between the path of movement and the swivelling axis for the movement.
The general arrangement in accordance with the invention described above and particularly the preferred embodiment of the arrangement in accordance with the invention also described above, thus includes a carrier element adapted so as to transfer one packing container blank at a time from the magazine to the conveyor. The carrier device swivels to and fro between the magazine and the conveyor, and thus moves within a limited range, so that the space requirement of the arrangement is small. A further factor contributing to a high degree to the compact design of the arrangement is that the support, adapted to co-operate with and to raise the passing packing container blanks, is placed within the range of movement of the carrier device. Thus the packing container blanks, transported by the carrier device during the transport from the magazine to the conveyor, are with all parts within the range of movement of the carrier device. This appreciably reduces the need for free space around the working arrangement in accordance with the invention.
The fact that the carrier plate retains its positional orientation during its arc-shaped movement between the first and the second position makes it possible, moreover, to return the carrier device after transporting and raising of a packing container blank directly to the first position at the outlet end of the magazine. Therefore, no raised packing container blank, located on the conveyor, hinders the return movement of the carrier device, since the raised packing container blank is inside the path of movement of the carrier plate. By reason of this the effective working speed of the arrangement can be increased and the need for any waiting periods is eliminated.
Further preferred embodiments of the arrangement in accordance with the invention have been given, moreover, the characteristics recited below.